1. Field of the Invention
The invention relates to a resist underlayer film-forming composition, a pattern-forming method, and a resist underlayer film.
2. Discussion of the Background
A reduction in processing size has progressed by utilizing a multilayer resist process in order to increase the degree of integration of semiconductor devices and the like (see Japanese Patent Application Publication (KOKAI) No. 2001-284209). The multilayer resist process includes applying a resist underlayer film-forming composition to a substrate to form a resist underlayer film, applying a resist composition to the resist underlayer film to form a resist film, transferring a mask pattern through exposure, and developing the resist film using a developer to form a resist pattern. The resist pattern is then transferred to the resist underlayer film by dry etching, the pattern of the resist underlayer film is transferred to the substrate by dry etching to obtain a substrate on which the desired pattern is formed.
In recent years, a further improvement in pattern-forming capability has been desired for the resist underlayer film-forming composition along with a reduction in size of the resist pattern and a reduction in thickness of the resist film. When using a known resist underlayer film-forming composition for the multilayer resist process, the resist underlayer film may be removed from the substrate after forming the resist film probably because the glass transition temperature (Tg) of the resist underlayer film-forming composition is higher than the heating temperature employed when forming the resist film. When wet etching is performed after forming the resist film, the pattern of the resist underlayer film may collapse due to external stimulation caused by wet etching.